EP0439953A2 - Vorrichtung zur Steuerung des Blindwiderstands einer Starkstromleitung - Google Patents

Vorrichtung zur Steuerung des Blindwiderstands einer Starkstromleitung Download PDF

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Publication number
EP0439953A2
EP0439953A2 EP90314147A EP90314147A EP0439953A2 EP 0439953 A2 EP0439953 A2 EP 0439953A2 EP 90314147 A EP90314147 A EP 90314147A EP 90314147 A EP90314147 A EP 90314147A EP 0439953 A2 EP0439953 A2 EP 0439953A2
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EP
European Patent Office
Prior art keywords
modules
line
series
transmission line
compensation
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Granted
Application number
EP90314147A
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English (en)
French (fr)
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EP0439953B1 (de
EP0439953A3 (en
Inventor
Stig Lennart Nilsson
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Electric Power Research Institute Inc
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Electric Power Research Institute Inc
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Publication of EP0439953A3 publication Critical patent/EP0439953A3/en
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Publication of EP0439953B1 publication Critical patent/EP0439953B1/de
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/18—Arrangements for adjusting, eliminating or compensating reactive power in networks
    • H02J3/1807—Arrangements for adjusting, eliminating or compensating reactive power in networks using series compensators
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
    • Y02E40/30—Reactive power compensation

Definitions

  • the present invention relates to apparatus for controlling the reactive impedance of a transmission line, and more particularly, to the insertion of series capacitance.
  • Reactive power control of AC transmission lines is desired to control power factor or control currents and voltages.
  • inductors and capacitors may be utilized.
  • Such systems are termed in the art a “static VAR.”
  • VAR stands for volt-ampere reactive.
  • a general discussion of reactive power control and actual experiments is contained in Bulletin 13-02 of the "International Conference on High Voltage Electric Systems” dated August 28 through September 3, 1988.
  • Switcheched series capacitors As illustrated in Fig. 1 of the drawings.
  • a transmission line 10 designated X L With the generator end being 10a and the load end 10b there are inserted series capacitors X1 through X n . These are switched by associated series switches S1 through S n .
  • These series switches S and capacitors X are in parallel with one another.
  • Fig. 2 also prior art, illustrates the practical design of capacitors X1 where it is actually a bank of series and parallel capacitors.
  • the dashed lines indicate the connection to the other parallel capacitors which are individually switched in and out of the circuit.
  • Other portions of the capacitor module X1 include the safety bypass switch 11 and a non-linear resistor 12.
  • the capacitor module might include a single mechanical bypass 13 which can control the percent series compensation capacitance level of the single unit as a one-time adjustment. This was discussed in a paper by E.W. Kimbark entitled “Improvement of System Stability by Switched Series Capacitors” (IEEE Transactions on Power Apparatus and Systems), Vol. PAS-85, Feb. 1966, pp. 180-188. In essence, a single capacitor bank was divided into two sections and a one-time mechanical switch provided for determining percent compensation.
  • a difficulty with the above scheme of using a bank of parallel capacitor modules is that the installed VAR capacity is excessive. And this is especially true if it is desired to utilize such compensation scheme for automatic and controllable variations in response to the monitoring of a parameter of the transmission line, such as subsynchronous oscillation, etc.
  • apparatus for controlling the reactive impedance of a transmission line where capacitive reactance is inserted in series in the line to compensate inductive reactance to a predetermined compensation level where the reactive impedance is lowered.
  • the apparatus comprises a plurality of three or more capacitor modules, each having a predetermined capacitive reactance, connected to each other in series to form a series combination of capacitor modules having a combined capacitive reactance represented by the arithmetic sum of the predetermined capacitive reactances.
  • the combined capacitive reactance provides a maximum compensation level where reactive impedance of the line is at a minimum level.
  • the predetermined capacitive reactance of each of the capacitor modules varies in magnitude from a maximum to a minimum in substantially geometric steps for providing modulation of the compensation level from the maximum to a minimum.
  • At least a portion of the modules includes solid state bypass switches with control inputs for conductively bypassing a selected module or modules in the series combination.
  • Control means are connected to the control inputs of substantially all of said modules for automatically varying the combined capacitive reactive in response to a change in one or more parameters of the transmission line.
  • Fig. 3 illustrates a series compensation capacitive reactance of an embodiment of the present invention. It includes a plurality of capacitor modules 14a through 14n which are connected to each other in series to form a series combination of capacitor modules having a combined capacitive reactance represented by the arithmetic sum of the capacitive reactances; these are designated X1, X2 through X n . They are series connected in the line between the generator end 10a and the load end 10b. As is apparent from examination of Fig. 3, any one or all of the capacitive reactances X1 through X n may be inserted in series in the transmission line 10 by selective activation of the bypass switches S1 through S n .
  • the combined capacitive reactance of all of the modules provides a maximum compensation level where the total reactive impedance of the transmission line is at a minimum level.
  • a practical limit may be 90%; that is, the capacitor reactance compensates for 90% of the inductive reactance due to the transmission line itself. This maintains the controllability and stability of the transmission line. Defending on the system use, such compensation may typically be at a 25 to 60% level. The 90% level would more typically be utilized in a feedback control system where it is desired to momentarily compensate for power or current surges.
  • a typical module 14a is illustrated in Fig. 4 which, while including the capacitive reactance X1, has an inductive reactance X L (which is only used to limit current surges when thryistors are turned on), a nonlinear resistor 16, a safety bypass switch 17, and inversely connected back to back switching thyristors 18a and 18b. These are connected across or in parallel with the capacitive reactance X1 to form a switch S1, as illustrated more schematically in Fig. 3 in connection with module 14a.
  • thyristors 18a, 18b would consist of several in series to meet voltage requirements; thus, they form a bypass switch to conductively bypass a selected module or modules in the desired series combination.
  • Safety bypass switch 17 may, in a practical installation, bypass several modules 14.
  • Each solid state thyristor switch 18a, 18b includes control inputs 19a, 19b which are connected to and controlled by an automatic control system 21. This senses the parameters of the transmission line 10, including the voltage, current and/or frequency, as indicated.
  • the control system is also connected to the other switches S2, S3, etc., of the modules 14a through 14 n , as illustrated in Fig. 3.
  • each capacitive reactance X1, X2, etc. must be designed for the maximum current expected in the transmission line when that particular module is to be used.
  • the capacitor module will include many capacitor units, C, in parallel and/or in series, as illustrated.
  • the individual capacitors represented in Fig. 5 may be purchased as capacitor "CANs" or a combination thereof.
  • a typical rating of one capacitor CAN might be with a capacitance of 4.7 microfarads rated at 14 kV with a current of 23 amperes.
  • Another type of CAN available commercially has the same current and voltage ratings but with 40 microfarads of capacitance.
  • the individual capacitor modules 14a-14n should have predetermined capacitive reactances varying in magnitude from a maximum to a minimum in substantially geometric steps for providing a smooth modulation of the compensation level.
  • the capacitive reactance values would follow a binary series of 1, 2, 4, 8, 16, 32, etc.
  • the smallest element X1 determines the smallest change of the compensation impedance which is possible.
  • the compensation level of the line is the highest. Since the impedance of a capacitor is inversely proportional to the value of the capacitance, the largest capacitance is used for X1 and the smallest for X n .
  • Fig. 6 illustrates how this is accomplished where a change of power ( power) may be expressed as the product of power and a change of capacitive reactance divided by the overall reactance. Thus, this is illustrated by the formula For the above equation the quantities are changes in power and net line impedance. As illustrated in Fig. 6, to accomplish this the controller 20' compares a setpoint (e.g., initial line current) with the existing line current, a transfer function is applied, and then the appropriate "S" switches actuated to give a desired X. This can be used for either a change of power flow or to correct for power surges in the line.
  • a setpoint e.g., initial line current
  • Rapid Adjustment of Network Impedance The purpose is to provide a smooth flow of power.
  • Other control objectives such as voltage, current, frequency or combinations thereof can similarly be accomplished.
  • the above equation assumes a simple model in that the networks at the two ends of the line are unaffected by the changes in power flow, which is obviously not the case.
  • the bypass thyristor switches 18a, 18b can be operated so fast that this assumption is valid for a short time period after the change.
  • the desired power flow can be achieved with a desired angle between the sending and receiving ends in automatic response to changes in measurement of the parameters of the transmission line, such as frequency, power flow, line currents, phase angle measurements, etc. This can dampen the transients in the power system.
  • Fig. 9 One particular use of a change of network impedance which will also impliedly cause a phase shift is illustrated in Fig. 9, where various power grids are geographically indicated as NW (for Northwest United States), Idaho, Utah, Arizona, Northern California and Southern California. Assuming an outtage in Southern California, power can be directed to Southern California via the shortest route (that is, via Northern California) by the adjustment of network impedance by the indicated phase shift networks 31 and 32. Each of these is, of course, a thyristor controlled series compensator of' an embodiment of the present invention. Phase shift network 32 can be adjusted to assure that no power is inadvertently transmitted via the longer route of Idaho and Utah.
  • SSO subsynchronous oscillations
  • a phase detector 34 responds to the line voltage to further specify the oscillation peaks and then a decision logic unit 36 determines the capacitance needed to shift to a safe region, as illustrated in Fig. 8.
  • the automatic control system of Fig. 7 would be in the unit 21, as illustrated in Fig. 4.
  • Fig. 10 shows another application of an embodiment of the present invention where there is illustrated a three-phase transmission line system with the phases A, B and C.
  • a generator side 41 and a load side 42 which are interconnected on the three phases by breaker switches (indicated by the 'Xs') of the trip/reclose type.
  • each series connected variable capacitance unit shown as 43a through 43c are in series in each phase; these units may be constructed as illustrated, of course, in Fig. 3.
  • the system would operate in the following manner under the control of the automatic control system 21 of Fig. 4. Assuming a fault to ground as indicated at 44 on phase B, the reactance 43b would have its bypass switches of its thyristor controlled series compensation banks closed so that any capacitance is removed from the circuit. This will immediately of course, since there is no compensation, increase the impedance of the circuit; thus, reducing the fault current and allowing the breakers to open under lower current conditions for phase B.
  • phase B and the breakers reclose, at which time the compensation of phases A, B, and C will be made equal again.
  • control means 21 is responsive to a fault in one line to temporarily increase impedance in such line (by bypassing all of the capacitive reactance -- thus reducing the effective compensation level) and reducing impedance (increasing to a maximum compensation level) on the two remaining lines.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Control Of Electrical Variables (AREA)
  • Supply And Distribution Of Alternating Current (AREA)
  • Networks Using Active Elements (AREA)
  • Control Of Ac Motors In General (AREA)
EP90314147A 1990-01-02 1990-12-21 Vorrichtung zur Steuerung des Blindwiderstands einer Starkstromleitung Expired - Lifetime EP0439953B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US459991 1990-01-02
US07/459,991 US4999565A (en) 1990-01-02 1990-01-02 Apparatus for controlling the reactive impedance of a transmission line

Publications (3)

Publication Number Publication Date
EP0439953A2 true EP0439953A2 (de) 1991-08-07
EP0439953A3 EP0439953A3 (en) 1992-09-16
EP0439953B1 EP0439953B1 (de) 1995-03-15

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EP90314147A Expired - Lifetime EP0439953B1 (de) 1990-01-02 1990-12-21 Vorrichtung zur Steuerung des Blindwiderstands einer Starkstromleitung

Country Status (6)

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US (1) US4999565A (de)
EP (1) EP0439953B1 (de)
AT (1) ATE120052T1 (de)
CA (1) CA2033459A1 (de)
DE (1) DE69017884T2 (de)
ZA (1) ZA9116B (de)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002041459A1 (fr) * 1999-12-03 2002-05-23 Hydro-Qhébec Appareil et methode de communication pour varier l'impedance d'une ligne de phase d'un tronçon d'une ligne de transport d'energie electrique
EP1309076A2 (de) * 2001-11-06 2003-05-07 Liebherr-Hausgeräte Ochsenhausen GmbH Netzteil für elektronische Baugruppe
WO2005119875A1 (en) * 2004-06-04 2005-12-15 Hydro-Quebec Switching apparatus and method for varying an impedance of a phase line of a segment of an electrical power line
GB2424772A (en) * 2005-04-02 2006-10-04 Paul Lenworth Mantock Power transmission system
US7235900B1 (en) 2000-11-14 2007-06-26 HYDRO-QUéBEC Switching apparatus and method for varying a phase line impedance of an electric power transport line section

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SE465596B (sv) * 1990-02-16 1991-09-30 Asea Brown Boveri Seriekondensatorutrustning med styrbar krets foer daempning av subsynkrona resonanssvaengningar
US5081591A (en) * 1990-02-28 1992-01-14 Westinghouse Electric Corp. Optimizing reactive power distribution in an industrial power network
US5198745A (en) * 1991-08-08 1993-03-30 Electric Power Research Institute Dynamic braking resistor system
US5202583A (en) * 1991-12-13 1993-04-13 Electric Power Research Institute Thyristor controlled series capacitor vernier control system
US5227713A (en) * 1991-08-08 1993-07-13 Electric Power Research Institute Vernier control system for subsynchronous resonance mitigation
US5374853A (en) * 1991-12-13 1994-12-20 Electric Power Research, Inc. Transient damping thyristor controlled series capacitor system
US5621305A (en) * 1991-12-13 1997-04-15 Electric Power Research Institute, Inc. Overload management system
US5424627A (en) * 1991-12-13 1995-06-13 Electric Power Research Institute Modular thyristor controlled series capacitor control system
WO1993018567A1 (de) * 1992-03-11 1993-09-16 Siemens Aktiengesellschaft Elektrisches energieübertragungssystem
EP0571642B1 (de) * 1992-05-18 1998-01-14 Siemens Aktiengesellschaft Verfahren und Vorrichtung zur Erzeugung eines Synchronisiersignals für einen Steuersatz zur Ansteuerung eines Stromrichterventils eines gesteuerten Serienkompensators
DE59205866D1 (de) * 1992-05-20 1996-05-02 Siemens Ag Verfahren und Vorrichtung zur Entlastung eines Kondensators eines gesteuerten Serienkompensators in Abhängigkeit der Belastung seines Ableiters
DE59203773D1 (de) * 1992-05-20 1995-10-26 Siemens Ag Verfahren und Vorrichtung zur Erkennung von Defekten in einem Ansteuersystem eines gesteuerten Serienkompensators.
US5422561A (en) * 1992-11-23 1995-06-06 Southern California Edison Company Automated voltage and VAR control in power transmission and distribution networks
WO1994024622A1 (en) * 1993-04-19 1994-10-27 Electric Power Research Institute Turnoff thyristor controlled series compensation system
US5642035A (en) * 1994-06-16 1997-06-24 Bio-Rad Laboratories Transfection high-voltage controller
US5825162A (en) * 1994-07-25 1998-10-20 Hitachi, Ltd. Electric power flow controller
JP2795183B2 (ja) * 1994-08-08 1998-09-10 松下電器産業株式会社 静止形無効電力補償装置
US5670864A (en) * 1995-05-26 1997-09-23 Pacific Scientific Company Adaptive automatic power capacitor for controlling controller a capacitor bank of a power distribution system
SE505745C3 (sv) * 1996-01-18 1997-10-06 Asea Brown Boveri Anordning foer styrning av en regulatorutrustning foer daempning av effektsvaengningar i en kraftlinje
EP0951126B1 (de) * 1998-04-15 2009-07-22 Mitsubishi Electric Corporation Kompensationsvorrichtung und Leistungsübertragungssystem damit
EP0982827A1 (de) * 1998-08-26 2000-03-01 Mitsubishi Electric Corporation Kompensatoranordnung und eine Kompensatoranordnung benutzendes Energieübertragungssystem
JP3715457B2 (ja) * 1999-02-25 2005-11-09 芝府エンジニアリング株式会社 直列補償装置
US6297940B1 (en) 1999-10-07 2001-10-02 Mcgraw Edison Company Protection system for devices in an electrical distribution network
US6737837B1 (en) * 2002-11-25 2004-05-18 Abb Ab Device and a method for control of power flow in a transmission line
US7095597B1 (en) * 2003-04-30 2006-08-22 Clipper Windpower Technology, Inc. Distributed static var compensation (DSVC) system for wind and water turbine applications
WO2007065383A1 (de) * 2005-12-07 2007-06-14 Siemens Aktiengesellschaft Elektroenergieübertragungseinrichtung
US20100133915A1 (en) * 2006-05-30 2010-06-03 Abb Research Ltd Thyristor controllied series capacitor adapted to damp sub synchronous resonances
DE202007000054U1 (de) 2007-12-17 2008-03-27 PCP Powercost Protector Company Ltd., Coventry Schaltungsanordnung zur Optimierung des Energieverbrauchs eines Verbrauchers an einem Wechselstromnetz
CN103004050B (zh) * 2010-06-03 2016-01-20 维斯塔斯风力系统集团公司 用于控制风力发电厂中的中央电容器的方法和控制装置
EP2397688A1 (de) * 2010-06-16 2011-12-21 Siemens Aktiengesellschaft Steuerungssystem für elektrische Energie und elektrische Energie erzeugende Anlage mit dem Steuerungssystem für elektrische Energie
US8731728B2 (en) * 2011-07-25 2014-05-20 General Electric Company Power distribution system
US8965588B2 (en) 2011-07-26 2015-02-24 General Electric Company Devices and methods for decentralized voltage control
US9570909B2 (en) 2011-07-26 2017-02-14 General Electric Company Devices and methods for decentralized power loss reduction control
US8838284B2 (en) 2011-07-26 2014-09-16 General Electric Company Devices and methods for decentralized Volt/VAR control
US8761954B2 (en) 2011-07-26 2014-06-24 General Electric Company Devices and methods for decentralized coordinated volt/VAR control
US8838285B2 (en) 2011-07-26 2014-09-16 General Electric Company Devices and methods for decentralized power factor control
US9444254B2 (en) 2011-08-30 2016-09-13 Cooper Technologies Company Bypass switch for a boost device
CA2863999A1 (en) 2013-02-01 2014-08-07 Abb Technology Ag Method and apparatus for mitigating sub-synchronous resonance in power transmission system
CN104836238A (zh) * 2014-02-08 2015-08-12 王海 高压智能开关交流电容器
US20150229203A1 (en) * 2014-02-12 2015-08-13 Gholamreza Esmaili Smart Resistor-Less Pre-Charge Circuit For Power Converter

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US4292545A (en) * 1979-04-16 1981-09-29 Electric Power Research Institute, Inc. Method and means for damping subsynchronous oscillations and DC offset in an AC power system
EP0289975A1 (de) * 1987-05-04 1988-11-09 Asea Brown Boveri Ab Reihenkondensatorvorrichtung

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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002041459A1 (fr) * 1999-12-03 2002-05-23 Hydro-Qhébec Appareil et methode de communication pour varier l'impedance d'une ligne de phase d'un tronçon d'une ligne de transport d'energie electrique
US7235900B1 (en) 2000-11-14 2007-06-26 HYDRO-QUéBEC Switching apparatus and method for varying a phase line impedance of an electric power transport line section
EP1309076A2 (de) * 2001-11-06 2003-05-07 Liebherr-Hausgeräte Ochsenhausen GmbH Netzteil für elektronische Baugruppe
EP1309076A3 (de) * 2001-11-06 2005-03-16 Liebherr-Hausgeräte Ochsenhausen GmbH Netzteil für elektronische Baugruppe
WO2005119875A1 (en) * 2004-06-04 2005-12-15 Hydro-Quebec Switching apparatus and method for varying an impedance of a phase line of a segment of an electrical power line
US7639460B2 (en) 2004-06-04 2009-12-29 Hydro-Quebec Switching apparatus and method for varying an impedance of a phase line of a segment of an electrical power line
GB2424772A (en) * 2005-04-02 2006-10-04 Paul Lenworth Mantock Power transmission system

Also Published As

Publication number Publication date
EP0439953B1 (de) 1995-03-15
ZA9116B (en) 1991-10-30
EP0439953A3 (en) 1992-09-16
CA2033459A1 (en) 1991-07-03
DE69017884D1 (de) 1995-04-20
US4999565A (en) 1991-03-12
ATE120052T1 (de) 1995-04-15
DE69017884T2 (de) 1995-07-06

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